Neil, An appropriate vang for your boat would use 1/4 line - no need for larger. Check some of the Harken small boat series - if you want a really 'cool' one, look at the new Laser cascade vang - just be careful you do not destroy your boom by over tensioning the vang. Most after- market vangs I have seen on boats are WAY to large. Seems the hardware guys want to have a 'two sizes fits all' inventory. The reason for not using "over sized' but indeed using the properly spec'ed parts is the eventual weight gain the boat takes on.One day your vang is too big but - hey ! no biggy - then your mainsheet, halyards, backstay adjusters some even want larger diameter shrouds and stays - this all adds up to weight - most of which is acting against the boat trying to stay upright! It is a cumulative thing. These (M-15's and 17's) are small boats - most of us have sailed centerboard dinghies that were larger and more powerful. We would think that a vang using 3/8" line would be overkill for all but the larger scows or similar powerful boats with BIG mainsails. PS - the Garhauer vang is rated at 1000 to 1150# s - and how much does your boat weigh ? Garhauer part are a little 'coarse' IMHO - Ronstan, Lewmar and of course Harken are much nicer product in most cases. Try to keep it light and simple - your boat and YOU will be happier and have more fun. GO 'ranting again' M-17 #316a - with the most cobbled up selection of parts for a vang you could imagine -3:1 cascade = 6:1 -1/4" and 1/8 "line. In a message dated 9/2/2009 10:39:49 A.M. US Mountain Standard Time, ndorf@surfbest.net writes: Looking for input on most cost effective boom vang for my 1985 M15, which currently does not have one. The tangs are already on the mast and boom. I was looking on the Harken site and also West Marine. These things can get expensive, especially when moving from those using up to 1/4" line to 3/8". Hoping to get away with spending less than $100 for something functional but user-friendly. So, any suggestions? Seems like the design shown as 4:1 Fiddle on the Harken web page is what I probably need, but will 1/4" line (parts 2655 and 2658) be sufficient (and comfortable) to use, or do I need to go 3/8" What about the West Marine model 380330 Vang - Mini? Anyone have experience with that setup? Other "build your own" suggestions? I would love to see a pic of what the original Montgomery setup was or even what the new Montgomery 15s are being shipped with. Thanks, Neil _______________________________________________ http://mailman.xmission.com/cgi-bin/mailman/listinfo/montgomery_boats Remember, there is no privacy on the Internet!